Fracturing tool and backup

ABSTRACT

A tool including a cone having a single ramp surface. A backup disposed on the ramp surface; a pusher having one or more slips. The pusher in contact with the backup and configured to force the backup along the ramp surface during use of the tool. A method for fracturing a formation through which a borehole passes.

BACKGROUND

In downhole industries including hydrocarbon exploration and recovery and carbon dioxide sequestration, it is often necessary or desirable to provide for seals and anchors within a tubular body. There have been many different types of configurations to effect such seals and or anchors, each having its advantages and drawbacks. Since the industries noted above experience nearly infinite particular situations, each of which might be better solved by one technology or another, there is a continuing need for alternate configurations to support the vast need and to provide enhancements in various instances.

Further, the art is always receptive to configurations that can reduce required axial length and reduce cost of production.

BRIEF DESCRIPTION

A tool including a cone having a single ramp surface; a backup disposed on the ramp surface; a pusher having one or more slips, the pusher in contact with the backup and configured to force the backup along the ramp surface during use of the tool.

A backup including a tubular body; a helical cut line through the body that terminates prior to reaching an end face of the body.

A method for fracturing a formation through which a borehole passes including applying an occluding member to a tool as claimed in claim 1, the tool having been installed in a borehole; pressuring up on the borehole against the occluding member and tool; and fracturing the formation.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

FIG. 1 is a cross sectional illustration of a seal and anchor tool;

FIG. 2 is a perspective illustration of the backup illustrated in FIG. 1;

FIG. 3 is a perspective illustration of an alternate backup ring for the configuration of FIG. 1; and

FIG. 4 is a cross sectional illustration of an alternate seal and anchor tool.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

Referring to FIG. 1, a seal and anchor tool 10 is illustrated in cross section that is actuated by axial compression force. A cone 12 appears at an uphole end of the figure and provides a single ramp surface 14 (i.e. eliminating an opposing ramp surface at an opposite axial end of a cone structure like that of the prior art) and in some embodiments an occluding member seat 16. The surface exhibits an angle ranging from about 2 degrees to about 20 degrees from a longitudinal axis of the cone in some embodiments. A seal 18 is disposed about the surface 14 and exhibits a matching angle surface 20 at an inside thereof to the angle of surface 14. The seal 18 provides an outside diameter surface 22 that is cylindrical in order to reasonably closely match an inside diameter surface 24 of a tubular in which the seal and anchor tool 10 are to be set. Adjacent the seal 18 is a backup 26 whose purpose is to prevent or substantially reduce extrusion of the seal 18 when the seal and anchor tool 10 experiences a pressure differential across the seal 18. It is to be appreciated from FIG. 1 that the diameter of the seal 18 appears greater than the diameter of the backup 26. This is intended since the seal diameter is, in one embodiment, configured with a diameter from about 0.005 to about 0.500 inch greater than that of the backup 26 in order to assure that the seal is fully seated and compressed to the surface 24 prior to the backup making contact with the surface 24. This configuration ensures that sufficient compressive load on the seal 18 will be imparted before the load axially applied to the tool 10 begins to be taken up by the backup 26 and the anchor (described below).

The anchor or slip ring pusher 28 is a full ring type that is designed to break apart into a number of slips 30 upon axial compression forcing the pusher 28 up the ramp surface 14. The slips 30 bite into the surface 24 as will be understood by one of ordinary skill in the art. Due to the breakage of the pusher 28, there are potentially, axial gaps that could allow the seal 18 to extrude under a sufficient pressure differential. The backup 26, because it bridges across such gaps, operates to prevent or reduce extrusion of the seal 18. The backup will also prevent or reduce extrusion of the seal annularly adjacent surface 24.

Based upon FIG. 1, an artisan skilled in the art will recognize that the convention two sided cone member is eliminated in the configuration of the disclosed tool. Rather only one cone is provided. This is contrary to conventional teaching and results in a reduced axial length of the tool as well as a reduced cost of manufacture thereof while still retaining the ability to support a fracturing operation. Both of these features will be well received by the art.

One embodiment of the backup 26 features a body 38 comprising single piece of material 40 composed at least in part of polymeric materials including but not limited to, Polytetrafluouroethylene (PTFE), Polyetheretherketone (PEEK), etc. and metal materials including but not limited to brass, aluminum, etc. The backup 26 is helically cut through a portion of the material but not all of the material. Reference is made to FIG. 2 wherein the material 40 is shown with a cut line 42 that terminates prior to reaching an end face 46 of the backup 26. It will be appreciated in the drawing that the cut line 42 does reach the opposite end face 48 of the backup 26 at 50 but it is to be understood that the cut line 42 could also terminate short of end face 48, if desired. In an embodiment, a range of uncut portion 44 over which the cut line 42 does not extend is from about 0.005″ to about 1.00″. The uncut portion 44 functions, in this embodiment, to provide for an initiation pressure before the backup will start to move up the ramp 14. This will help avoid premature actuation and give more positive feedback during intended deployment. As the backup 26 moves up the ramp, once the uncut portion(s) 44 tear, the diameter increases by the material 40 sliding over itself along the cut line 42. Since the material stays circumferentially complete, any axial openings along the slips 30 will be bridged by the backup 26. The result is zero extrusion gap and minimal actuation force required.

Referring to FIG. 3, the backup 26 is similar but not identical to that of FIG. 2. Rather, in FIG. 3, there are two cut lines 52 and 54 through material 40. Each cut line 52 and 54 are helically arranged making two helical parts 56 and 58 that are nested with each other. At least one, and as shown both of the cut lines 52 and 54 terminate prior to reaching an end face 60 leaving uncut portion 62 and 64. A range of uncut portion 62 and 64 over which the cut lines 52 and 54 do not extend is from about 0.005″ to about 1.00″. It is to be understood that more cut lines may be added to produce more helical parts if desired. In the case of embodiments such as FIG. 3, the uncut portions serve not only to provide for initiation pressure before deployment as in FIG. 2 but also to hold the helical parts together prior to deployment. In this embodiment of backup 26 as in the previous embodiment, both annular and axial extrusion gaps are minimized or eliminated.

It is to be appreciated that in the case of FIGS. 2 and 3, the backup is not limited to employment in the tool described herein (and as noted the tool does not necessarily require the particular backup) although they do work well together. The backup as described may be employed with any other tool requiring a backup and the tool described herein may use other backups that provide sufficient resistance to seal extrusion.

In another embodiment, referring to FIG. 4, a tool 70 is illustrated that eliminates the seal 18 as described above but maintains other components of the tool 10 of FIG. 1. It has been determined that the backup 26 can be used alone to provide sufficient differential pressure holding capability to support a fracing operation without a seal 18. Therefore, for certain operations that are cost sensitive, it may be beneficial to employ the tool illustrated in FIG. 4.

It is also contemplated for any or all of the components/tools described above that materials such as a controlled electrolytic metallic material (Intallic™ commercially available from Baker Hughes, Houston Tex.) or other dissolvable or disintegrable material be employed so that the entirety or some portion of the entirety of the tools may be removed through dissolution via natural borehole fluids or applied fluids at an appropriate time.

The tool embodiments disclosed herein are particularly suited to fracturing a formation through which a borehole passes while reducing expense in production of the tool, reducing longitudinal axial length of the installed to and optionally reducing costs for removal of the tool. The fracturing operation comprises: installing one of the embodiments set forth above in a borehole; applying an occluding member on the tool; pressuring up on the borehole against the occluding member and tool; fracturing a formation adjacent the borehole and removing the tool from the borehole.

The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should further be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the particular quantity).

While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. 

What is claimed is:
 1. A tool comprising: a cone having a single ramp surface; a backup disposed on the ramp surface; a pusher having one or more slips, the pusher in contact with the backup and configured to force the backup along the ramp surface during use of the tool.
 2. The tool as claimed in claim 1 wherein the ramp surface is at angle of from about 2 degrees to about 20 degrees from a longitudinal axis of the cone.
 3. The tool as claimed in claim 1 wherein the backup is configured to bridge annular and axial gaps when in use.
 4. The tool as claimed in claim 1 wherein the backup comprises a tubular body including a helical cut line that terminates prior to reaching an end face of the body.
 5. The tool as claimed in claim 4 wherein the body includes an uncut portion ranges from about 0.005 inch to about 1.00 inch.
 6. The tool as claimed in claim 1 wherein the backup comprises a polymeric material.
 7. The tool as claimed in claim 1 wherein the backup comprises a controlled electrolytic metallic material.
 8. The tool as claimed in claim 1 wherein the backup comprises a metal material.
 9. The tool as claimed in claim 1 further comprising a seal.
 10. The tool as claimed in claim 9 wherein the seal has an outside diameter that is larger than an outside diameter of the backup and the pusher.
 11. The tool as claimed in claim 10 wherein a difference in the diameter of the seal and the backup or pusher is from about 0.005 to about 0.500 inch.
 12. A backup comprising: a tubular body; a helical cut line through the body that terminates prior to reaching an end face of the body.
 13. The backup as claimed in claim 12 wherein the body includes an uncut portion that ranges from about 0.005 inch to about 1.00 inch.
 14. The tool as claimed in claim 12 wherein the backup comprises a polymeric material.
 15. The tool as claimed in claim 12 wherein the backup comprises a controlled electrolytic metallic material.
 16. The tool as claimed in claim 12 wherein the backup comprises a metal material.
 17. A method for fracturing a formation through which a borehole passes comprising: applying an occluding member to a tool as claimed in claim 1, the tool having been installed in a borehole; pressuring up on the borehole against the occluding member and tool; fracturing the formation.
 18. The method as claimed in claim 17 further comprising installing the tool as claimed in claim 1 in the borehole
 19. The method as claimed in claim 17 further comprising removing the tool from the borehole.
 20. The method as claimed in claim 19 wherein the removing is by dissolving or disintegrating the tool. 